Tuatara: Volume 1, Issue 1, September 1947

A Key to the Littoral Asteroids of New Zealand

A Key to the Littoral Asteroids of New Zealand

The following key is designed for use by anyone without a specialised knowledge of echinoderms. Consequently the characters used are external ones, and the key is purely artificial. Only the shallow water species are included, except in the case of one or two species likely to be met with in fishermen's trawls down to 50 fathoms. None of the rarer forms are listed. The distribution is indicated in terms of the marine provinces, using the following abbreviations: A, Aupourian, i.e., the northern half of the North Auckland peninsula; C, Cookian, i.e., the remainder of the North Island, and the northern two-thirds of the South Island; M, Moriorian, i.e., the Chathams group; F. Forsterian, i.e., the southern third of the South Island, Foveaux Strait and Stewart Island; R. Rossian, i.e., the Auckland and Campbell Islands.

Spines of aboral surface stouter than those bordering the ambulacral groove, and equal in length to the latter. Arms 6-11, usually 11, and commonly of unequal size owing to regeneration, of autotomised parts.

Literature: This unfortunately is very scattered, but most important is Mortensen, Th. (1925), Vidensk. Medd. Dansk naturh. Foren., 79, p. 261, where further references will also be found. This publication is in the library of the Royal Society of New Zealand.

A, Asterodon miliaris, upper surface of one arm. B, Pentagonaster pulchellus, upper surface of one arm. C, Asterina regularis, lower surface of one arm. D, Sclerasterias mollis, cross-section of an arm, showing arrangement of spines. E, Stegnaster inflatus, lower surface of one arm. F, Stichaster australis, cross-section of an arm to show arrangement of granules and spines. G, Coscinasterias calamaria, crosssection of an arm to show spines. H, Astrostole scabra, cross-section of an arm to show spines. I, Psilaster acuminatus, side view of marginal plates of an arm showing arrangement of the spines on inferomarginal plates. J, Persephonaster neozelanicus, side view of marginal plates of an arm showing arrangement of spines on both superomarginal and inferomarginal plates. K, Diplodontias dilatatus, upper surface of an arm. L, Psilaster acuminatus, upper surface of one arm.